Consumers use nail coatings to cosmetically enhance the appearance of their nails or protect the nails from the abuses found in their everyday environment. However, nail coating compositions typically lack the durability desired by consumers or are difficult to apply or remove in terms of time and/or effort. The lack of durability is often evidenced by a chipping or peeling of the coating soon after the original coating has been applied, requiring at least in part a reapplication of the coating in an attempt to recreate the aesthetic appearance or the therapeutic benefits of the original nail coating.
Lilley (U.S. Pat. Nos. 6,391,938, 6,803,394 and 6,599,958) discloses light cured nail coatings that are applied to natural nails and/or artificial nail tips for cosmetic purposes.
Ellingson et al. (U.S. Pat. No. 6,306,375) discloses long wear nail polish compositions having defined surface properties, as well as kits, films and methods of their use.
Ellingson et al. (U.S. Pat. No. 6,123,931) discloses polyurethane and polyacryl nail polish compositions useful as coatings for mammalian nails as well as methods of their use.
Ellingson et al. (U.S. Pat. No. 6,136,300) discloses long wear nail polish compositions having adhesion, toughness and hardness characteristics useful as coatings for mammalian nails as well as methods of their use.
Smith III et al. (U.S. Pat. No. 6,080,414) discloses films and kits useful as polishes for mammalian nails and methods of their use, reportedly having long wear characteristics.
Farer et al. (U.S. Pat. No. 6,656,483) discloses cosmetic compositions containing polyurethane for application to the skin and nails.
Farer et al (U.S. Pat. No. 6,156,325) and Carrion et al, (U.S. Pat. No. 6,555,096 and related published US Patent Application No. 2002/0102222) disclose nail enamel compositions containing a urea-modified thixotropic agent.
Sirdesai et al. discloses a polymerizable thixotropic oligomeric composition for sculpting artificial fingernails which is non-yellowing, and which maintains its shape when formed and polymerizes rapidly under actinic radiation.
Traditional nail coatings generally include two varieties: polish type, which cure by solvent evaporation, and polymer type, which cure by chemical reaction. Polymer type materials include, for example, powder/liquid systems and gel systems.
Gel systems, in contrast to the traditional polish and other polymer-type systems, particularly ultraviolet-cured gel systems, often comprise a gel that may be brushed onto the nails, cured, and shaped to create lifelike artificial nails. As compared with traditional polishes or other non-gel polymer-type systems, gel systems are relatively easy to use, are applicable in less time, are lightweight on the nail, have no odor (or only minimal odor), are durable, and have a high quality shine.
While thicker nail coatings may in general be more desirable due to their richer color and/or greater durability of the finished nail coating, it can be challenging to reasonably rapidly and substantially cure the entirety of the coating after its application. This is especially true for thicker and/or more highly pigmented UV-curable gel-based nail coating systems. This may be due, in part, to the nature of these coatings. For example, while UV light may readily penetrate the outermost regions of the coating composition to initiate the cure, the higher levels and/or darker hues of certain pigments in some coating compositions may limit penetration of the UV radiation into the innermost regions of the applied gel coating composition and thus increase the time required to substantially cure the entirety of the coating.
Often there is also a trade off in the choice of nail coatings between a particular coating's durability and its ease of removal. For example, some prior art gel coating compositions, while durable, cannot be readily removed by typical “soak-off” procedures and require a more laborious removal process. Alternatively, while some prior art gel coating compositions are very easily removed; those properties may lead to premature chipping and/or peeling of the coating, requiring additional maintenance or reapplication to stabilize the coating's overall appearance.
Thus, there is a real need in the art for gel systems that can be formulated to provide durable curable nail coatings, especially those capable of being removed relatively easily by ‘soak-off” procedures. There is also a need for gel systems that are capable of being applied easily and/or in less time than typically required by prior art gel systems or polishes. Further, there is a need for gel systems that provide such coatings regardless of the required coating color while providing a richness of color throughout the nail coating. Such gel coatings may give a more appealing and defect free appearance. The present invention is directed to these and other important ends.